Smooth pursuit preparation modulates neuronal responses in visual areas MT and MST.
Smooth pursuit preparation modulates neuronal responses in visual areas MT and MST.
复制标题
平滑的追踪准备调节视觉区域 MT 和 MST 的神经元反应。
DOI：
10.1152/jn.00636.2014
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发表时间：
2015
影响因子：
2.5
通讯作者：
Ferrera,VincentP
中科院分区：
文献类型：
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作者：
Ferrera,VincentP
灵长类动物能够通过平滑的眼球运动来追踪移动的小视觉目标。平滑追踪的目标运动是由视觉皮层中颞叶区和颞叶区神经元发出信号的。在这项研究中，我们训练猴子在有移动目标的情况下开始或停止平稳的追求，以测试这种决定是否反映在“走”和“不走”过程的相对强度上。我们发现，运动反应的增益在很大程度上取决于猴子是否被指示启动或停止追求，从而表明对追求启动的自愿控制。我们发现，MT和MST区域的神经元对运动目标的反应幅度在不动试验中也显著降低（平均2.1峰值/秒）。与行为增益减少相比，神经反应减少的幅度较小。在神经元的方向选择性，空间选择性，或反应可靠性相关的追求启动或不存在显著差异。在围棋实验中，眼速变异性与目标运动开始后的射速变异性呈负相关，而在不围棋实验中则没有，这表明眼动和眼动皮层活动代表了负反馈控制器的错误信号。我们推测，MT和MST区域的视觉运动信号调制可能是平滑追逐开始的第一个视觉皮质事件之一，并且小的早期反应调制可能被下游区域放大以产生全或无运动反应。
Primates are able to track small moving visual targets using smooth pursuit eye movements. Target motion for smooth pursuit is signaled by neurons in visual cortical areas MT and MST. In this study, we trained monkeys to either initiate or withhold smooth pursuit in the presence of a moving target to test whether this decision was reflected in the relative strength of “go” and “no-go” processes. We found that the gain of the motor response depended strongly on whether monkeys were instructed to initiate or withhold pursuit, thus demonstrating voluntary control of pursuit initiation. We found that the amplitude of the neuronal response to moving targets in areas MT and MST was also significantly lower on no-go trials (by 2.1 spikes/s on average). The magnitude of the neural response reduction was small compared with the behavioral gain reduction. There were no significant differences in neuronal direction selectivity, spatial selectivity, or response reliability related to pursuit initiation or the absence thereof. Variability in eye speed was negatively correlated with firing rate variability after target motion onset during go trials but not during no-go trials, suggesting that MT and MST activity represents an error signal for a negative feedback controller. We speculate that modulation of the visual motion signals in areas MT and MST may be one of the first visual cortical events in the initiation of smooth pursuit and that the small early response modulation may be amplified to produce an all-or-none motor response by downstream areas.